CONYERS, Ga. -- Rockdale County officials said Friday night with "high confidence" that a child playing with a lighter cause the tragic fire Tuesday night that claimed the lives of four children, all younger than 10, in a Conyers duplex.

Dan Morgan, chief of Rockdale County Fire-Rescue said the determination had been made after an interview with the surviving child in the tragedy.

Morgan said they believe surviving 6-year-old boy was the one playing with the lighter. The child is being referred to the state Department of Family and Children's Services for counseling and treatment.

Rockdale County Fire-Rescue spokesman Michael Morris said there were no working smoke detectors in the home -- he said the one smoke detector in the unit was downstairs, but that it did not have a battery in it. He said there was not a smoke detector upstairs.

Eight-month-old Deon Glass, Jr., 3-year-old Armoni Roberts, 7-year-old Dar'Shawn Glass and 9-year-old Ah'Dariya Glass died on the second floor of their duplex on Pinedale Circle. Dar'Shawn would have turned 8 next Saturday.

The children's brother, who turned 6 on Wednesday, survived with minor injuries after their mother Reeba Glass threw him out a second-story window before jumping herself. She received severe burns and is being treated at Grady Hospital's burn unit in Atlanta. Darnell was treated and released after being transported to Children's Healthcare of Atlanta at Egleston.

The children's maternal grandmother, Rosetta Mitchell, escaped injury but was extremely distraught. She was helping comfort her daughter and making funeral arrangements.

Conyers Police Chief Gene Wilson said four of his officers arrived at the family's home within seconds of the fire being reported at 11:05 p.m. Tuesday and tried to put out the blaze with hand-held extinguishers, but the fire was too strong.

Wilson said the bulk of the fire was on the second floor of the home and while it failed to burn through the roof, windows were blown out by the fierce blaze. The upstairs portion of the house was destroyed. The four children who died were found in two upstairs bedrooms.

Wilson said there had been a fire in the first floor fireplace, but it may not have caused the larger fire. The Bureau of Alcohol, Tobacco and Firearms took samples from that area of the home to find out if an accelerant was used.

The cause of the fire is still under investigation, and has not yet been determined.